Safety of Phenylalanine
Although it is a natural product, phenylalanine safety issues still need to be kept in mind -- especially for people taking it in supplement form. For example, if you have certain medical conditions, you may need to closely watch your intake of phenylalanine. Safety precautions also include making sure that the manufacturer of your supplements is trusted and reputable.
Is Phenylalanine Safe?Phenylalanine is an amino acid essential for human nutrition. It is found in many foods, but it is also used in some dietary supplements. While a normal dietary intake of phenylalanine is not dangerous for most people (see Dangers of Phenylalanine), it is not known if phenylalanine supplements are equally safe. You may not be able to take these supplements safely if you have:
- Phenylketonuria (PKU)
- Any allergies, including allergies to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant
You should also be sure to tell your healthcare provider about all of the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Specific Phenylalanine Warnings and PrecautionsWarnings and precautions to be aware of concerning the safety of phenylalanine include the following:
- If you have phenylketonuria (PKU), do not take phenylalanine supplements. It is essential that people with PKU limit their intake of phenylalanine.
- Phenylalanine supplements can interact with some medications (see Phenylalanine Drug Interactions for more information).
- If you decide to use phenylalanine supplements, be aware that what you see on the label may not reflect what is in the bottle. For example, some herbal supplements have been found to be contaminated with heavy metals or prescription drugs, and some have been found to have much more or much less of the featured ingredient than their label states. Therefore, make sure the manufacturer of your phenylalanine is trusted and reputable. It is a good sign if a manufacturer abides by the rules of Good Manufacturing Practices (GMP) for drugs. It is also a good sign if a product has the United States Pharmacopoeia (USP) seal, which means that the product has been independently tested and shown to contain the correct ingredients in the amounts listed on the label. Your pharmacist is a good resource for information about which manufacturers are most reputable.
- It is not known if phenylalanine supplements are safe for pregnant or breastfeeding women (see Phenylalanine and Pregnancy and Phenylalanine and Breastfeeding).